From the Old to the New World have come not only men but mice, peas and pigeons, cabbages and goats—multitudes of animal and vegetable settlers that have thrived in their adopted land

In the spring of 1847 Thomas Woodcock, president of the Natural History Society of Brooklyn, New York, received from England a crate containing several pairs of small, dingy birds. He released them in a city park. None survived the following winter. Woodcock repeated his experiment with a similar lack of success each of the following three or four springs. In either 1851 or 1852 his persistence was rewarded, and Passer domesticus , the house sparrow, joined Rattus norvegicus , the house rat, Mus musculus , the house mouse, and Homo sapiens , the house builder, in the ranks of America’s major settlers.

All four of these immigrant species continue to prosper here despite the way the first three annoy the fourth. Many other varieties of once-foreign fauna and flora also thrive in the hospitable hemisphere to which they have come.

Many animal interchanges took place in the distant past between Siberia and Alaska via the land bridge which repeatedly has risen above and sunk below the waters of Bering Strait. Paleontologists have found that some animals that long seemed typically western hemisphere types—such as bison and black bears—actually may have done most of their evolving in the eastern hemisphere and crossed the bridge only a few million years ago. Others, such as horses and camels, were absent here when Columbus arrived but had originated here and traveled to the Old World late in the course of their development. In the last few hundred centuries the Indians have been the only notable new form of life to cross the bridge. (The dogs they brought with them from Siberia, apparently their only companions, were scarcely different from native wolves and coyotes.)

The Indians settled into inconspicuous niches throughout most of the hemisphere and provided minimum competition for native species. Ever since 1492, however, most immigrants have been the opposite of inconspicuous and uncompetitive. The hemispheric balance of nature still gyrates dizzily in response to them.

By far the most obvious in impact are the domesticated plants that now blanket millions of acres. With only a few notable exceptions all the cereals, fruits, and table vegetables commonly grown in this hemisphere originated in Asia, Africa, or Europe and have arrived here since Columbus. The Admiral himself brought along a wide variety of seeds on his second voyage, and most of the other explorers did the same. Jacques Cartier, for instance, reported that on his 1541 voyage up the St. Lawrence River, “We sowed seeds of our country, as cabbages, turnips, lettuces and others, which grew and sprung up out of the ground in eight days.”

Oddly, the better an immigrant plant has thrived here, the lower the U.S. human immigration quota is likely to be for the region from which the plant originated. Among non-native cereal grains, for instance, by far the most important is wheat, which originated in the Near East; only rye, a decidedly minor crop, may have originated in Europe, and probably low-quota southeastern Europe at that. Of fruits, apples are from the Caspian Sea region; peaches and apricots, from China; watermelons, from Africa; cherries, from the Near East; oranges, lemons, and grapefruit, from southeast Asia. Only such lesser ones as raspberries can claim any European ancestry. Of vegetables, peas are from Central Asia; radishes, from China; spinach, carrots, and lettuce, from western Asia; cabbage, from the eastern Mediterranean area. Only the likes of Brussels sprouts and rutabagas are from the high-quota lands of northern Europe.

Two of the most important plants used as human food in this country are wholly American in origin but had to go abroad in order to gain acceptance here. One of these, the white potato, was domesticated far back in prehistoric times by the Indians of the high Andes. So important was this vegetable there that Aymara, a language spoken by Indians of southern Peru, had 209 different terms for different kinds of potato. Hantha , for instance, meant “an old potato with black skin and white flesh.” Other terms indicated where the potato was to be grown or how well it resisted frost and so on.

To reach North America the potato had to travel first to Spain about the end of the sixteenth century. A few decades later it landed in the British Isles. What seem to have been the first potato plantings in this country were made by Irish immigrants to New Hampshire about 1720. The tomato took an even longer way round. Probably a native of either Mexico or the Andes, it apparently was never of much importance to (he pre-Columbian Indians who domesticated it, but when it arrived in southern Europe at the end of the sixteenth century, it caught on quickly, just possibly because some promoter had the bright idea of calling it la pomme d’amour . Two centuries later Thomas Jefferson, always ready to try something new, brought a few plants back from Europe. But here the hint of aphrodisiac qualities meant to many that the fruit was certainly sinful and possibly poisonous. Not until near the end of the last century did the love apple finally begin to attain general respectability in America.